Roubaix Formation (SD*)
Paleoproterozoic*
Secs. 32 and 33, T. 4 N., R. 4 E., 1 mi west of map area in Galena-Roubaix district, Lawrence Co., SD (Bayley, 1972).
Midcontinent region*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).